During the past decade, there has been widespread interest in a class of materials evidencing optical properties suitable for use in fiber optic and integrated optic technology. Among the most prominent of such materials has been silicon dioxide, a composition known for its ability to successfully guide light. Unfortunately, workers in the art have encountered a modicum of difficulty in guiding light through this material because of the absence of convenient claddings which must evidence indices of refraction below that of the core material, namely, pure bulk silicon dioxide. Heretofore, efforts to overcome this limitation have focused upon the use of fluorine or boron doped claddings or the use of an organic coating on the surface of the silicon dioxide. Unfortunately, the doping effort proved costly and yielded only minor changes in the index of refraction. In marked contrast, the organic coating was able to effect large changes in refractive index but proved to be thermally unstable.